How often do/should you check your SPARE tire pressure?

[GoFrogs]

For those of us who are lucky enough to get a spare tire (donut or full-size), how often do you take the time to check the spare's air pressure?

Today, while rotating my [base] WRX's tires, I checked my spare's pressure before putting it on as a place holder and it was at 20.9 psi (140 kpa ).

I think it has been several years since I last checked (last time I self-rotated).

Car is a 2019 w/69833 mi and on its 3rd set of tires (Dunlop Sport Maxx :\ --> Conti DWS06 --> Mich PS AS4 .

I don't normally keep an inflator in the car, so it would have been poopy big time to discover my spare's pressure air a 1/3 of what it should needs to be.

Do you run a flexible stem extender from the spare for easier checking, or do you just remove the 3 layers of stuff to get to the tire and check?

I think I'll go to Harbor Freight or Tractor Supply Co. and see if they have flexible stem extenders. Worst case is I'll go to an auto parts store (more expensive) and see what they have.

Thoughts, suggestions, other?

[Elbert Bass]

Theoretically you should check the spare every time you check tire pressures/change oil/rotate tires.
I would not put "extenders" on - that is a good way to loose ALL pressure in your spare tire.

Yup, properly maintaining a vehicle requires a bit of effort on your part.
Three layers? It's a Subaru! - all you need in the back is gallon of oil, a funnel, and a jug of coolant...

[GoFrogs]

Originally Posted by Elbert Bass

Theoretically you should check the spare every time you check tire pressures/change oil/rotate tires.
I would not put "extenders" on - that is a good way to loose ALL pressure in your spare tire.

Yup, properly maintaining a vehicle requires a bit of effort on your part.
Three layers? It's a Subaru! - all you need in the back is gallon of oil, a funnel, and a jug of coolant...

understand the involved w/mx part. I normally have the tire place I got the tires do the rotation (as part of the 4-tire purchase plan). But since I had extra time this past weekend, and not wanting the hassle of taking it to them (again holiday weekend), then waiting 3+ hours...I just decided to do it myself for funnzies.

Yes, 3 layers. For me there is the Subaru trunk mat; then there is the trunk carpet; then there is the big foam underfloor; then there is the foam tool bucket w/tools....so yes, three layers.

As far as the gallon of oil, funnel, and jug of coolant; I'm not at that stage of ownership yet (not quite at Bug/Hawk-eye coolness factor).


Checking twice a year is okay, but it should be even be more than that. The outside tires are easy and just need a quick visual to see if they are remotely low and/or getting a gauge on them isn't hard. The spare is trickier because it lives silently in the trunk, out of sight.

As far as extenders go, Amazon is having Prime Days soon and 2x 12" extenders are $8. I can use Teflon tape on the threads for a better seal. Yes, adding anything in line w/the valve that allows the air to move could cause an issue, but we will see.

I figure my luck w/Amazon is on par w/the local auto parts stores but cheaper. As it is now, Autozone/Advance/NAPA wants 'arms' or 'legs' for most of the products on the pegs.

[lefty o]

a smart person would check it at least twice a year. most people check it when they get a flat, and need the spare.

[Patrick Olsen]

I think the answer for most people (myself included) is "not often enough". I got lucky and found my wife's spare was flat a couple years ago - bad valve stem on a 8yo Mercedes. I've stopped on the roadside to help someone with a flat, only to find that their spare was also flat - had to take them to the next exit to go put air in it. I actually just bought valve stem cores a couple weeks ago because I need to replace the one on my beater Impreza's spare - still haven't actually done that, but I bought them!

[krzyss]

I check when swapping summer and winter tires. Twice a year.

Krzy***347;

[Big-E]

I haven't until this past weekend. 2015 FXT and 2016 STI were both at 20psi; I'm stupid for not checking them regularly.

I keep a 12vdc air-pump, a tire-plug kit, and valve-stem cores and related installation tool in the car as well.

[GoFrogs]

Originally Posted by Big-E

I haven't until this past weekend. 2015 FXT and 2016 STI ere both at 20psi; I'm stupid for not checking them regularly.

no worries to all...

Well, I have the 2x 12" valve stem extenders in. They are braided stainless steel, so I will put some heat shrink tubing on them to keep scratch damage to a minimum.

If the picture thingy is working, I will show pics of my progress and show how it's going to work...or not work.

Just need some free time...........

[Charlie-III]

I check a few times a year. I also usually have a 12VDC pump in the car.

Funny thing, some cars have a TPMS in the spare. More than once I have had peeps complain that they have a pow pressure warning but the 4 tires check out fine. I then ask if they checked the spare.

[GoFrogs]

Originally Posted by Charlie-III

I then ask if they checked the spare.

That's forward thinking...but I don't think Subaru is there yet. For a company bent on safety, to me, that ranks right up there with mirror turns (on all cars) and blind spot monitoring....

Here are those pictures.

3 Layers....


Layer 1 (only applies to those w/the trunk mat)



Layer 2



Layer 3



Layer 3.5



Finally, the tire...



Tire flipped to access the air valve



The braided extenders. Left has heat shrink and duct tape; Right is bare.



Starting air pressure



Final air pressure with an inflator



Not as flexible as I thought...



Well, I call this a fail. But at least I know what doesn't work. The extenders are not as flexible as I thought. The length was fine, but moving the extenders twerked the valve stem in unnatural positions while positioning the extender to be in a reachable position. I didn't want to damage the valve stem and decrease its integrity.

I'm not sure if the 90* dually stem adapters would help either; as they too are metal. There are rubber valve stem extenders, but those were only 7.5" in length.

So, back to the idea board.